My Apple 2 Emulator

See also: Java Applet Apple 2 Emulator. (By the way, on these pages 'Apple 2' should probably be 'Apple II', but since I support the Web Accessibility Initiative I decided to use the former instead of the latter.)

I've made my emulator available primarily to allow folks to have a look at the source code, as frequently emulators do not include their source. If you're wanting an emulator that's actually useful, especially under Windows, I'd recommend downloading AppleWin (see the links below, you want the "applewin95complete.zip" file). AppleWin spends several minutes performing a calibration when first run. Let it do that, then read its included help file for instructions.

Introduction

My very first computer was an Apple 2e. From 1984 to 1990 I learnt to program in Applesoft BASIC and 6502 machine code. (I played lots of games too ).

In 1989 at university, I started using IBM PCs. The programming was much easier and friendlier on the PCs, first with Turbo Pascal, then with Turbo C. Turbo C converted me to the PC and I was using my old Apple less and less.

This emulator was mostly written between 1993 and 1995. Since then, little has been done apart from minor tweaks. It is still not complete. Although it does quite a bit, I would still like it to do the 80-column card and extended 64K properly, plus emulate the IOU and MMU chips (so it passes the Enhanced IIe self-test).

Things It Does

Emulates an Apple 2+ and Apple 2e (original and enhanced). Will auto-detect what ROM it is using and configure itself appropriately.
Emulates a full 64K memory (48K + 16K language card). Reports 128K memory under ProDOS, but this does not work properly - attempt to use the /RAM volume and ProDOS will crash.
Emulates Disk 2 interface and auto-detects DOS / ProDOS ordered disk images and nibble disk images. Allows reading and writing. Can be compiled to correctly emulate disk drive speed so ProDOS can format disks.
Has support for ProDOS large disk volumes (up to 32MB). This is a home-made emulation and doesn't look like anything 'real'.
Has Parallel Interface Card emulation.
Has clock card emulation. This is also home-made, and does not emulate any existing clock card. (Requires a special 'driver' - see PRODOS1.DSK)
Supports text, lo-res, high-res, full and split screen displays. An authentic chararacter font is used. Flashing characters work.
Supports my home-made parallel link between the PC and a real Apple computer. Can be set up so the emulator reads real Apple disks remotely on the real Apple.
Twiddles the PC speaker appropriately.

Things It Does Not Do

The extra 64K memory does not work properly.
The IOU and MMU chips are not emulated (at least not so the self-test passes).
Disk drive images cannot be changed on-the-fly.
No serial port support.
No 80-column text or double-high-res graphics.
No Mockingboard support.

Download

Download appleemu.zip (651K) and un-zip using folder/directory names. This is a raw directory dump from my hard drive. It includes a working emulator and a ProDOS mass-storage disk image (PRODOS1.DSK). Full source code is included, plus project files for Borland C++ 3. I am releasing all my source code into the public domain.

Archive directory structure:

APPLEEMU - Main source code and executable directory. Required files:
- APPLE.EXE - Emulator
- APPLE.ROM - A ROM image from a real Apple
- CHARSET.BIN - Authentic text character set
- CENTRONI.ROM - Parallel Interface Controller ROM (for printer port)
- MASSSTOR.ROM - ProDOS mass-storage (32MB) device ROM
- DISK.ROM - Disk 2 floppy controller ROM
- CLOCK.ROM - Clock card ROM
Other files include all the source code files and Borland C++ project and desktop files.
APPLEEMU\A2I - Some Apple <--> IBM communications code.
APPLEEMU\DOC - Miscellaneous documentation.
APPLEEMU\ROMS - Miscellaneous ROM images.
APPLEEMU\TASM280 - 6502 cross-assembler. This directory has the source code for the ROM firmware for my home-made mass-storage and clock card devices.
APPLEEMU\TMP - Old video code? I don't really know what this is!
APPLEEMU\UTIL - The startings of a utility to manage files inside disk images.

Ignore references to my home address of "14 Whittington Avenue..." - I haven't lived there for years! Email me instead.

Quick Start

Start the emulator by running APPLE.EXE. Since there are no DISK6A.DSK or DISK6B.DSK disk images (for slot 6, drives 1 and 2 respectively), the emulator will just hang there. Press Ctrl-F12 to reset it (same as pressing Reset or Ctrl-Reset on a real Apple). The emulator will stop. Enter PR#5 to start up the mass-storage device. ProDOS will load. Check out the slot allocations and date/time settings. When you're done, press F1 or Alt-SysRq to quit.

Copy your own disk images to DISK6A.DSK and DISK6B.DSK.